THE TAXONOMIC VALUE OF FRUIT WALL STRUCTURE IN THE GENUS ANNESORHIZA (APIACEAE)

A study of the fruit wall structure of 12 species of Annesorhiza Cham. & Schlechtd. has shown a wealth of taxonomically useful characters at both the generic and infrageneric levels: firstly, the presence of en ormously expanded and lignified vascular bundles, which appears to be a unique generic character; secondly, a remarkable type of heteromorph ic wing symmetry [only in A. macrocarpa Eckl. & Zeyh. and A. nuda (Ait .) B.L. Burtt], in which all the sepaline ribs and the two commissural petaline ribs have expanded to form wings; and thirdly, the presence of lignified cells in various positions, which can be used to distingu ish some of the species. The genus Annesorhiza is poorly known but the external and internal fruit wall structure provide valuable informati on which contributes to a better understanding of infrageneric relatio nships.